This is the second renewal of a training grant on Cellular and Neurobiological Aspects of Aging. The training program covers research in the departments of Pathology and Anatomy & Cell Biology, the Center for Neurobiology and Behavior, as well as the Alzheimer's Disease Research Center (ADRC). Many of the faculty, who are part of this training grant are also members of the ADRC, which is headed by Dr. Michael Shelanski. Although there is an emphasis on Alzheimer's Disease, it is not the only focus of this training program. The research interests of the participating faculty include the study of other neurodegenerative diseases, such as Parkinson's Disease, Alexander's Disease and Amyotropic Lateral Sclerosis, as well as cell biological problems, such as the mechanisms of cell death, the dynamics of the cytoskeleton, the cessation of the cell cycle and the action of growth factors and their receptors. One of the strengths of the training program is the wide variety of research interests of the participating faculty, which has enabled us to attract good candidates. We are asking for continued support for four pre-doctoral and four post- doctoral trainees. The pre-doctoral trainees will be chosen from the pool of graduate students who are being trained by the participating faculty and will be selected on the basis of their research interests and qualifications. A Unified Program involving all the graduate programs at Columbia University College of Physicians and Surgeons has recently been instituted. As Part of the Unified Program, all the first year students will be supported by the Office of Graduate Affairs. We are now able to choose among the students who already have selected their mentors. The pool of students available to the participating faculty is large and the qualifications of the students are excellent. In addition to paying for all the first year students, Columbia University is demonstrating their support of the training program by supplementing the salaries of the trainees in order for them to be able to meet the high cost of living in New York. Postdoctoral trainees apply directly to the laboratory of the participating faculty and subsequently apply to be supported by the training grant. The participating faculty members are all funded and have well equipped laboratories with all the research equipment necessary to do high quality cell and molecular biology.